1. Field of the Invention
The present invention relates generally to a paper sheet conveyance device and an image forming apparatus.
2. Description of the Related Art
A conveyance member (conveyance roller) that conveys a paper sheet is known as a paper sheet conveyance device that is used for, for example, an image forming apparatus.
Japanese Laid-open Patent Publication No. 2012-180189 describes that, in a paper sheet conveyance device, when the interval between a preceding paper sheet and a paper sheet following the preceding paper sheet is narrower than a specific distance while paper sheets are sequentially conveyed, the interval is corrected to the certain distance. Specifically, the actual interval between the preceding paper sheet and the following paper sheet is calculated by using the difference between the time point at which a paper sheet back end sensor detects the back end of the preceding paper sheet and the time point at which the paper sheet back end sensor detects the back end of the following paper sheet. When the calculated actual distance is shorter than the specific distance, while a conveyance roller that is conveying the preceding paper sheet is being driven, only a conveyance roller that is conveying the following paper sheet is stopped. In this manner, when the interval between the preceding paper sheet and the following paper sheet is shorter than the specific distance, the interval can be corrected to the specific distance. This prevents the paper sheets being conveyed from overlapping each other and from being jammed due to the too short interval between the preceding paper sheet and the following paper sheet.
In order to stop only the conveyance roller that is conveying the following paper sheet while the conveyance roller that is conveying the preceding paper sheet is being driven, the paper sheet conveyance device described in Japanese Laid-open Patent Publication No. 2012-180189 has to be configured to separately drive and stop the conveyance roller that is conveying the preceding paper sheet and the conveyance roller that is conveying the following paper sheet. Separately driving and stopping the conveyance roller that is conveying the preceding paper sheet and the conveyance roller that is conveying the following paper sheet requires complicated control for driving and stopping the conveyance rollers, which may increase the cost of the device.